The invention generally relates to percutaneously introduced occlusion catheters, and more particularly to an occlusion catheter having an atraumatic guiding tip formed of an elastomeric polymer. More particularly, the present invention pertains to an occlusion catheter in which the atraumatic guiding tip is formed of entirely of polymer, polymer reinforced with a shape memory or superelastic material, or entirely of a shape memory or superelastic material. Still more particularly, the present invention pertaint to an occlusion cathter having at least one lumen suitably configured to introduce or withdraw body fluids from a patient into which the cathter is placed, and/or for sensing a condition within the body, such as, for example, pressure or flow rate in the region of the catheter. Yet still more particularly, the present invention pertains to an occlusion catheter having a first catheter member with a first lumen extending longitudinally through the first catheter member and open at a distal end of the first catheter member; a second catheter member having a second lumen extending longitudinally through the second catheter member and open at a distal end of the second catheter member, the second catheter member is positioned over and in spaced apart relationship relative to a proximal section of the first catheter member forming an annular space between the second catheter member and the first catheter member, the proximal section of the first catheter member resides within the second lumen of the second catheter member and the first catheter member extends beyond the distal end of the second catheter member, a third catheter member having a third lumen extending longitudinally through the third catheter member and open at a distal end of the third catheter member; the third catheter member is positioned over a distal section of the first catheter member, the third catheter member having a distal section that extends distally from a distal end of the first catheter member such that the first lumen and the third lumen are in fluid flow communication, whereby the second and third catheter are spaced apart from each other along a longitudinal axis of the first catheter member with the first catheter member extending there between; the atraumatic guiding tip member being joined to a distal end of the third catheter member; and an expandable member, such as a balloon, coupled to the second catheter member and to the third catheter member, such that the space between the second catheter member and the third catheter member is within an area bounded by the expandable member.
Balloon catheters generally comprise an elongated catheter shaft with an expandable balloon on the distal end of the shaft, and are used in a number of different medical procedures, including, for example, angioplasty, stent placement, occlusion, drug deliver, etc. The catheter is introduced through a percutaneous introducer sheath and maneuvered into the patient's blood vessels until the balloon is properly positioned within the body, such as at the stenotic site to be dilated or at a site requiring occlusion, drug delivery or other procedure such as stent placement.
It is often desirable for balloon catheters to have very low profiles in order to facilitate passage of the balloon across severe and remote vascular obstructions. High strength materials are commonly required in the design of balloon catheter components to prevent shaft buckling when the balloon is inflated. Additionally, high strength materials are required so that torque applied to the proximal end of the catheter results in rotation of the distal tip of the catheter. High flexibility materials are also commonly required in the design of balloon catheter components to maintain a low-profile and avoid trauma or perforation of the blood vessels while the catheter is maneuvered through the patient's tortuous vasculature.
Conventional balloon catheters, particularly those intended for vascular occlusion, do not adequately balance the need for proximal segment stiffness with the need for low profile, flexible distal segment and trackability through the tortious vascular pathway without entry into collateral vessels. Therefore, a need exists for a low profile occlusion catheter with a high strength and relatively stiff proximal segment and a flexible distal segment with an atraumatic tip having a design that permits tracking along the major vessels while preventing entry into collateral vessels.